Outer Serrated Toothed Lock Washers

Purchase the Xiaoguo® Outer Serrated Toothed Lock Washers, which are highly suitable for large-sized fasteners. The outer teeth of the washers will provide a larger locking area when used with large-sized fasteners, resulting in a more reliable effect.

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Product Description

The types of Outer Serrated Toothed Lock Washers are mainly classified based on aspects such as tooth shape structure, load-bearing strength, and special functions.

（1）DIN 6798

The DIN 6798 standard is the most widely used specification for Outer Serrated Toothed Lock Washers, and it mainly consists of three forms:

①Outer serrated locking ring

The teeth are on the outer ring and are arranged in an overlapping manner, providing the largest contact area.

②Inner serrated locking ring

The teeth are on the inner ring and are suitable for small-head screws.

③Conical ribbed locking ring

Conical structure, 90° countersunk angle

Outer Serrated Toothed Lock Washers

（2）BW vs EOW

According to the load strength classification, the Outer Serrated Toothed Lock Washers is divided into standard type and heavy-duty type.

① BW Standard Type

It has regular tooth depth, fits normal industrial use and common assembly work.Common uses: electronic goods, general machinery, automation equipment.

② EOW Heavy Duty Type

It comes with deeper teeth and better anti-loose performance, suited for places with heavy vibration and heavy load.Common uses: auto parts, high vibration machinery, construction projects and steel structures.

（3）Special Function

①EOW Overlap

A special overlapping tooth structure, specially designed for applications with relatively weak torque. Compared to the common external tooth type, it is suitable for uneven supporting surfaces, has a larger contact area, and is conducive to load distribution.

②Large/Narrow Band

According to the requirements of different application spaces, (RDEFL/RDIFL) and (RDIFS) are provided to meet the varying contact area demands.

③Double Toothed Washer RDD

Both the inner and outer surfaces are serrated, suitable for applications where higher anti-loosening requirements are needed.

FAQ

（1）Are Outer Serrated Toothed Lock Washers effective against high vibration？

Yes, the external tooth gasket is more suitable for high-vibration environments than the internal tooth gasket, because it has a larger contact area between the teeth and a deeper engagement.

（2）Will the teeth damage soft materials like aluminum or plastic?

That’s right. The sharp teeth will dig into softer materials and leave dents or even cracks.For aluminum parts, you can put a flat washer between the lock washer and the workpiece to play a buffering role.As for plastic parts, don’t use external tooth washers directly. It’s better to choose internal tooth washers or use a bigger flat washer instead.

（3）What is the typical hardness of the spring steel Outer Serrated Toothed Lock Washers?

After heat treatment, the hardness is usually HRC 40–50 (approximately 400–530 HV).

Outer Serrated Toothed Lock Washers

Size		1.7	2.2	2.7	3.2	3.7	4.3	5.3	6.4	7.4	8.4
d	min=nominal size	1.7	2.2	2.7	3.2	3.7	4.3	5.3	6.4	7.4	8.4
d	max	1.84	2.34	2.84	3.38	3.88	4.48	5.48	6.62	7.62	8.62
dc	max=nominal size	3.6	4.5	5.5	6	7	8	10	11	12.5	15
dc	min	3.3	4.2	5.2	5.7	6.64	7.64	9.64	10.57	12.07	14.57
	t	0.3	0.3	0.4	0.4	0.5	0.5	0.6	0.7	0.8	0.8
Number of Teeth	min	9	9	9	9	10	11	11	12	14	14
per 1000 unitsskg		0.02	0.03	0.045	0.06	0.11	0.14	0.28	0.36	0.5	0.8
For Nominal Thread Diameter		M1.6	M2	M2.5	M3	M3.5	M4	M5	M6	M7	M8

Size		10.5	13	15	17	19	21	23	25	28	31
d	min=nominal size	10.5	13	15	17	19	21	23	25	28	31
d	max	10.77	13.27	15.27	17.27	19.33	21.33	23.33	25.33	28.33	31.39
de	max=nominal size	18	20.5	24	26	30	33	36	38	44	48
de	min	17.57	19.98	23.48	25.48	29.48	32.38	35.38	37.38	43.38	47.38
	t	0.9	1	1	1.2	1.4	1.4	1.5	1.5	1.6	1.6
Number of Teeth	min	16	16	18	18	18	20	20	20	22	22
per 1000 unitsskg		1.25	1.6	2.3	2.9	5	6	7.5	8	12	14
For Nominal Thread Diameter		M10	M12	M14	M16	M18	M20	M22	M24	M27	M30